Patents by Inventor Chih-Heng Chu

Chih-Heng Chu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7956827
    Abstract: A current driving apparatus and method using a pulse width modulation (PWM) technique to display a desired gray level for passive matrix organic light emitting diode (PMOLED) display applications is disclosed. The current driving circuit includes a memory, a logic and a segment driver. The memory stores a desired gray level, the logic comprises a counter and provides a predetermined bias time, and the segment driver provides a constant current to the PMOLED display based on the desired gray level and the predetermined bias time. The segment driver provides a constant current to the PMOLED display until the counter value reaches the desired gray level, and the counter is first counted zero for the predetermined bias time and then increments by one for every other cycle.
    Type: Grant
    Filed: July 8, 2005
    Date of Patent: June 7, 2011
    Assignee: Himax Technologies Limited
    Inventors: Chih-Heng Chu, Ming-Cheng Chiu
  • Patent number: 7911484
    Abstract: A source driver comprising a frame memory, a first line buffer, and a second line buffer. The frame memory stores bits of pixel values of an image. The first line buffer then sequentially latches the bits of the pixel values from the frame memory with a first address index. The second line buffer then sequentially latch the bits of the pixel values from the first line buffer with a second address index, which is different from the first address index, and writes the bits of the pixel values back to the frame memory, such that the image is scrolled. The present invention also provides a method of refreshing the frame memory in a source driver.
    Type: Grant
    Filed: September 11, 2007
    Date of Patent: March 22, 2011
    Assignee: Himax Technologies Limited
    Inventors: Tian-Hau Chen, Chih-Heng Chu
  • Publication number: 20090066707
    Abstract: A source driver comprising a frame memory, a first line buffer, and a second line buffer. The frame memory stores bits of pixel values of an image. The first line buffer then sequentially latches the bits of the pixel values from the frame memory with a first address index. The second line buffer then sequentially latch the bits of the pixel values from the first line buffer with a second address index, which is different from the first address index, and writes the bits of the pixel values back to the frame memory, such that the image is scrolled. The present invention also provides a method of refreshing the frame memory in a source driver.
    Type: Application
    Filed: September 11, 2007
    Publication date: March 12, 2009
    Applicant: HIMAX TECHNOLOGIES LIMITED
    Inventors: Tian-Hau CHEN, Chih-Heng Chu
  • Publication number: 20070236426
    Abstract: A method for driving a display is disclosed. The method is particularly useful for driving a passive matrix organic light-emitting diode (PMOLED) display. The method includes the following steps. First, a preparation gray level and a current gray level for the pixels within a scan line to be displayed are detected. Then, a pre-charge voltage and a discharge voltage for the pixels within the scan line are adjusted according to the preparation gray level and the current gray level.
    Type: Application
    Filed: June 21, 2006
    Publication date: October 11, 2007
    Inventors: Chih-Heng Chu, Ming-Cheng Chiu, Jeh-Chuen Chen
  • Publication number: 20070182854
    Abstract: A drive circuit and method for screen horizontal scroll and an electronic device using the same are provided. Channel data is shifted between channels, such that the distance and the rate required for the screen horizontal scroll are achieved. The scrolled (shifted) channel data will be written back into a memory inside the electronic device to update the memory. The memory sends out the updated channel data, without re-calculating the channel data by a microprocessor. With channel data shifted and written back into the memory, the screen image shown in the electronic device is horizontally scrolled.
    Type: Application
    Filed: April 19, 2006
    Publication date: August 9, 2007
    Inventors: Tian-Hau Chen, Chih-Heng Chu, Zc-Chen Chen
  • Patent number: 7224622
    Abstract: A method for writing data into the memory, especially a method of preventing the data from overwriting for the write operation, is disclosed. The invention provides a control device for a memory system, which utilizes at least two layers of latches to hold the inputted data from a data bus and the data which prepares to be written into memory respectively. According to the control of communication between two layers of latches by the control device, the new inputted data of the succeeding write operation will not overwrite the data of the current write operation, thereby reducing the limitation for the cycle of writing (CYCW) and increasing the write speed.
    Type: Grant
    Filed: February 14, 2005
    Date of Patent: May 29, 2007
    Assignee: Himax Technologies, Inc.
    Inventors: Chih-Heng Chu, Ming-Cheng Chiu
  • Publication number: 20070035482
    Abstract: A driving circuit for driving a plurality of display cells, includes: a plurality of first switches, a plurality of driving units coupled to the first switches, and a plurality of second switches respectively corresponding to the first switches. The first switches receive and output a plurality of data signals, respectively. Each driving unit is utilized for driving at least one display cell of a row of display cells according to a data signal. The driving circuit outputs a driving signal corresponding to a specific data signal received and outputted by a specific first switch.
    Type: Application
    Filed: August 11, 2005
    Publication date: February 15, 2007
    Inventors: Yu-Wen Chiou, Chih-Heng Chu, Ming-Cheng Chiu, Lin-Kai BU
  • Publication number: 20070008254
    Abstract: A current driving apparatus and method using a pulse width modulation (PWM) technique to display a desired gray level for passive matrix organic light emitting diode (PMOLED) display applications is disclosed. The current driving circuit includes a memory, a logic and a segment driver. The memory stores a desired gray level, the logic comprises a counter and provides a predetermined bias time, and the segment driver provides a constant current to the PMOLED display based on the desired gray level and the predetermined bias time. The segment driver provides a constant current to the PMOLED display until the counter value reaches the desired gray level, and the counter is first counted zero for the predetermined bias time and then increments by one for every other cycle.
    Type: Application
    Filed: July 8, 2005
    Publication date: January 11, 2007
    Inventors: Chih-Heng Chu, Ming-Cheng Chiu
  • Publication number: 20060181921
    Abstract: A method for writing data into the memory, especially a method of preventing the data from overwriting for the write operation, is disclosed. The invention provides a control device for a memory system, which utilizes at least two layers of latches to hold the inputted data from a data bus and the data which prepares to be written into memory respectively. According to the control of communication between two layers of latches by the control device, the new inputted data of the succeeding write operation will not overwrite the data of the current write operation, thereby reducing the limitation for the cycle of writing (CYCW) and increasing the write speed.
    Type: Application
    Filed: February 14, 2005
    Publication date: August 17, 2006
    Inventors: Chih-Heng Chu, Ming-Cheng Chiu